Remote control slide projector



Dec. 28, 1965 N. A. SAUPPE REMOTE CONTROL SLIDE PROJECTOR 5 Sheets-Sheet1 Filed March 28, 1962 INVENTOR. /V0 e/M4/V/4. Wa 35 4 J Dec. 28, 1965N. A. SAUPPE 3,225,652

REMOTE CONTROL SLIDE PROJECTOR Filed March 28, 1962 5 Sheets-Sheet 2 5859 FYG. 4.

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6/ I 5/6 7 40 I BY 49 J 1965 N. A. SAUPPE REMOTE CONTROL SLIDE PROJECTOR5 Sheets-Sheet 3 Filed March 28, 1962 y/0 v #2 a.

INVENTOR. Nae/MAIN 5147/ 5 FIG. 0.

United States Patent 0 3,225,652 REMOTE CONTROL SLIDE PROJECTOR NormanA. Sanppe, Pasadena, Calif., assignor to Spindler dz Sanppe, LosAngeles, Calif., a corporation of California Filed Mar. 28, 1962, Ser.No. 183,098 32 Claims. (Cl. 8828) This invention relates to slideprojectors, and more particularly to a projector having one or moreslide magazines associated with selectively operable remote controlmeans by which any desired slide selected at random can be transferredbetween either magazine and the projecting assembly together with meansfor identifying to the audience the particular slide then beingprojected, and embodying numerous other features to be explained indetail hereinbelow.

Slide projectors for film transparencies have been proposed heretoforeutilizing slide magazines and having means by which the operator or aperson giving an oral presentation supplemented by visual aids candisplay slides successively but only in the order in which they arearranged in the magazine. Not infrequently there is need for displayingthe slides out of order. Additionally, there is need for exhibitingslides in a greater number than can be accommodated in a single magazineas well as for selecting any slide from either magazine at random forsuccessive presentation in any desired time sequence. Prior to thepresent invention there has been no mechanism available capable ofsatisfying these important needs.

By the present invention there is provided a portable slide projectorhaving a plurality of rotary supports for a corresponding number ofslide magazines disposed on opposite sides of an intervening slideprojecting assembly. Desirably, the magazines proper comprise circulardrums each having radially arranged slide storage cells opening throughthe outer periphery of the drum and indexable to a position aligned withthe slide seating slot of the projector assembly. This assembly isprovided with power iriven slide transfer means effective to transferthe slide from either magazine into projecting position provided bothmagazines are locked against indexing movement.

The remote control mechanism for the projector includes a control boxhaving selector switches operable to select any slide at random fromeither magazine and including means for indicating the particular slideas well as the magazine from which it was selected. The selection of aslide effects the operation of relays and control devices to rotate themagazine containing the selected slide into alignment with theprojecting assembly and for then locking the magazine against movementwhile simultaneously transferring the selected slide into projectingposition and for then displaying the slide while activating a digitalindicator to apprise the audience of the identity of the selected slide.

Other features of the invention include lightweight, compact magazinedrums so designed as to be readily removable simply by lifting them froma supporting turntable without need for operating any fastener devicesor disconnecting any electrical circuits. Furthermore, the magazinedrums are returnable to the turntable in any random position and arethereupon locked for rotation with the turntable. Such random reassemblyof the magazines to the turntable does not interfere in any way with theability of the control mechanism immediately to select any slide forpresentation Without need for making any adjustment or experiencing anydelay while processing a preliminary orientation or aligning operation.These unusual operating characteristics are ob- 3,225,652 Patented Dec.28, 1965 tained by locating related pairs of selection contactors on astationary support for the turntable and in the path of wipingcontactors on the juxtaposed interior portions of the magazine.

Other features of the projector relate to constructional details of themagazine turntable rotatable such as the cooperating stop and detentmeans which are responsive to electrical actuation to control theprecise stopping of the magazine opposite the proper loading positionfor any selected slide.

The digital slide indicator means is of a dual character and includes anindicator positioned for convenient viewing by the audience andindicating the particular slide being displayed as well as the magazinefrom which it originated. A related adjunct performs the same functionsfor the projector operator.

Other features of the invention include interlock means for safeguardingagainst jamming of the projector due to improper or a speedy reversal ofthe applied operating signals as for example a change of operatinginstructions to the control mechanism while the first selectedinstructions are in progress.

Accordingly it is a primary object of the present invention to provide anew and improved automatic slide projector having a remote controlstation by which the projector can be operated to project any desiredslide selected either at random or in succession as filed in the storagemagazine.

Another object of the invention is the provision of a slide projectorhaving a plurality of magazines and control means by which any slide canbe selected at random from either magazine for projection.

Another object of the invention is the provision of a remote controlautomatic slide projector having one or more slide magazines resting bygravity on indexing transport means therefor and incorporating selectioncontrol mechanism and featuring provision for the fast-action removaland replacement of the magazines at any time without need for operatingfasteners or electrical circuit disconnects of any kind.

Another object of the invention is the provision of an automatic slideprojector having a slide magazine indexable into any of a series ofoperating positions to display the slides contained therein in anydesired random order and wherein the magazine proper may be removed andreassembled to the indexing support in any position without, however,interferring with resumption of display in predetermined random order.

These and other more specific objects will appear upon reading thefollowing specification and claims and upon considering in connectiontherewith the attached drawings to which they relate.

Referring now to the drawings in which a preferred embodiment of theinvention is illustrated:

FIGURE 1 is a perspective view of a projector embodying the presentinvention arranged in one of several typical modes of use and with theprojector itself in a separate room from the viewing audience;

FIGURE 2 is a top plan view of the projector itself shown on an enlargedscale;

FIGURE 3 is a plan view on an enlarged scale of the remote control forthe projector;

FIGURE 4 is a vertical sectional view on an enlarged scale through oneof the magazines and its indexing assembly as viewed along line 44 onFIGURE 2;

FIGURE 5 is a horizontal sectional view on an enlarged scale takenthrough the indexing drive for the turntable and the stop mechanismtherefor;

FIGURE 6 is a top plan view of the selector contactors taken along line66 on FIGURE 4;

FIGURE 7 is a fragmentary horizontal sectional view a of the interlockbetween the turntable and the magazine as it appears along line 7-7 onFIGURE 4;

FIGURE 8 is a fragmentary'sectional view of the tumtable stop mechanismtaken along the broken line S8 on FIGURE FIGURE 9 is a fragmentaryvertical sectional View of the turntable drive taken along line 99 onFIGURE 5; and

FIGURE 10 is a fragmentary schematic of the control circuitry for theprojector but showing only one of the units and one of the tens slideselection switches and the associated indicator pilot lamps.

Referring more particularly to FIGURES 1 to 2, there is shown apreferred embodiment of the invention comprising the projector unititself designated generally 10 and arranged to project a slide imageonto a screen 11 over the heads of an audience seated about a table 12.The operator of the projector might be seated in chair 13 at the forwardend of the table in a convenient position to manipulate the controlbuttons of the slide selector unit 14. It will be understood theselector box 14 is connected to projector 10 through cabling 15 as is adigital slide identification indicator 16 here shown as mounted in arecess in the room wall adjacent the lower margin of screen 11. Ifdesired, indicator device 16 can be mounted on table 12 or in any otherconvenient audience viewing position.

Projector 10 includes a main frame or base 18 having any suitable slideprojecting assembly 19 positioned centrally thereof and includingsuitable optical means for transmitting an image from a slide ontoscreen 11. Projecting assembly 19 will be understood as including a highintensity lamp enclosed within housing 20 having the louvered cover 21through which cooling air is circulated by a motor-driven fan enclosedwithin the base of the projector. Spaced laterally to either side ofprojecting assembly 19 are a pair of slide magazine drums A, B eachprovided with a large number of radially disposed slide storing cellsarranged to be indexed past a slide receiving slot 24 extendingcrosswise of projecting assembly 19 in accordance with customarypractice and in which the slides are seated while being projected ontothe screen. Each of the magazines A, B is mounted on an individualturntable arranged to be rotated past slide projecting slots 24 in amanner which will be described in greater detail presently.

The various relays and control components for operating the projectorand for transferring selected slides between the magazines andprojecting slot are enclosed within an appropriate casing 25 attached tothe projector frame 18 and supporting thereon a manual switch panel 26and attached switches manipulatable by the operator in a manner and forpurposes which will be discussed below. Means for locking each of themagazines and for driving the same are mounted on the projector frameclosely beside the rim of the respective magazines and are enclosedwithing housings 27, 27'. It is pointed out at this time that identicalcomponents of the two magazines and of the associated operatingmagazines are designated by the same reference numerals, those formagazine B being distinguished by the addition of a prime mark.

Referring more particularly to FIGURES 4 to 9, it will be understoodthat each of the identical slide magazines, as magazine A, includes acylindrical drum conveniently formed of molded plastic and each providedwith radially arranged slide receiving cells 30 opening outwardlythrough the peripheral wall of the magazines. Slidably seated in each isa rectangular slide having a frame 31 provided along its inner edge witha downturned hook 32 useful in transferring the slides to and from themagazines and in looking the slides within the magazines. To this end,hooks 32 extend radially inward beyond the side wall of a central well33 opening upwardly through the bottom of each magazine and having abottom formed by a disc 34. This disc is supported against an inwardlyprojecting shoulder 35 formed on a sleeve 36 held suitably secured tothe upper or top end wall 37 of the magazine. The means here shown forholding disc 34 in this assembled position comprises an invertedcup-shaped member 38 having a snug frictional fit within the upper endof sleeve 36. The upper end of sleeve 36 is curled outwardly to form arolled handgrip rim 39 by which magazine A may be grasped in the palm ofthe hand when assembling it to the projector turntable or whenwithdrawing the magazine therefrom.

The large bore well 33 formed centrally of magazine A has a closetelescopic fit over the cylindrical base 40 of a boss 42 upstanding fromprojector frame 18. It is pointed out that the upper end of the baseportion 40 of boss 42 is provided with an upstanding thin annularlocking flange 44 encircling boss 42 projecting into the notch of hooks32 carried by the slides. Locking flange 44 is continuous except for anupwardly opening notch 45 in direct alignment with the slide receivingslot 24 in projecting assembly 19. Notch 45 also extends upwardly alongthe side wall of boss 42 and provides a passage through which the thinslide transfer lever arm reciprocates while transferring a slide fromthe magazine into slide receiving slot 24 of the projecting assembly.The slide transfer mechanism will be described below.

It is also pointed out that notch 45 permits hook 32 of the individualslides to become disengaged from locking flange 44 of the stationaryboss 42. The locking tangs or hooks 32 of all slides except one presentin the magazine are normally engaged or interlocked with locking flange44 and are held thereby against displacement from the magazine storagecells 30.

Magazine assembly A seats against the upper surface of a turntable ring48 having a central opening 49 fitting about the enlarged base 40 of aboss 42. The turntable is held detachably assembled to base 40 by aspring keeper ring 50 seating in an annular groove 51 and rotates onball bearings 53 held captive in depressions formed in a retainer plate54. Screwed into a threaded bore of turntable ring 48 is a locator screw55 the head of which is receivable in any one of the annular row oflocator recess 56 formed in the bottom of the magazine, there preferablybeing a separate locator recess 56 located in predetermined positionbelow each slide receiving cell 30 of the magazine. The rim edges ofrecesses 56 may be beveled to facilitate seating the magazine over thehead of locator screw 55. From the foregoing it will be understood thatwhen assembling the magazine onto the turntable, the operator merelylowers it over boss 42 until the magazine comes to rest on the turntablefollowing which it is rotated to the slight extent necessary to assurethat the locator screw 55 seats in any adjacent one of recesses 56. Whenso seated it is known that the slides within the magazine are preciselylocated with respect to each of the turntable indexing positions ornotches.

Another feature of the turntable is the fact that its flanged rimincludes a plurality of locator notches 60 (FIGURE 5) of the generalcontour shown, there being one such notch opposite each slide seatingcell 30 of the magazine. These notches seat the locking pawl servingsuch an important function in the accurate indexing of the turntable andthe details of which will be described below. Located below notches 60is an annular smoothsurfaced driving flange 61 integral with theturntable and engaged by the resilient covering on the periphery of theturntable drive pulley 62 (FIGURE 9).

The indexing control for turntable 48 will now be described withparticular reference to FIGURES 5, 8 and 9. The housing 27 for thesecomponents is accurately secured to projector frame 18 as by screws 64.The L- shaped heavy-duty pawl 67 is journalled to the base of thehousing 27 by a vertical pivot pin 68 with pawl tooth 69 positioned toengage within any individual notches 6-0 on the rim of the turntable.The outer end of an arm 70 rigidly secured to pawl 67 supports a tensionspring 71 having its other end anchored to a pin 72, the spring 71 beingeffective to urge tooth 69 of the pawl into firm seating engagement witha notch 60. The pawl is disengageable from notches by energizing asolenoid 75 mounted within housing 27 and having an armature 76connected through link 77 of adjustable length to pawl 67 by means of apin 78. When de-energized, the solenoid armature is held in its extendedposition by spring 71. However, when the solenoid is energized thearmature is attracted to the left as viewed in FIGURE 5 thereby pivotingthe pawl out of the notch 60 in which it is then seated therebyreleasing turntable 48 for clockwise rotation.

Referring more particularly to FIGURES 5 and 8, it is pointed out thatpawl 67 also operates a microswitch. To this end an arm 80 rigidlysecured to the edge of pawl 67 supports adjustable bolt 81 at its lowerend having a head positioned to contact the operating plunger of adouble-throw microswitch 83. Accordingly, it will be understood thatmovement of pawl 67 between its locked and unlocked positions isaccomplished by energizing and de-energizing its operating solenoid 75and acts additionally to shift the microswitch 83 from its closedposition in one direction to an alternate closed position. In one of itsclosed positions switch 83 is effective to energize the turntable drivemotor whereas in its alternate position it is effective to energize amotor operating the slide transfer mechanism. These motor and thecontrol circuits therefor will be described below.

Referring now to FIGURES 5 and 9, it is pointed out that the turntabledrive pulley 62 is fixed to a shaft 88 extending upwardly through an arm89 pivotally supported about shaft 90 of the turntable drive motor 91,the latter being located within projector housing 18. A drive gear 92keyed to the upper end of shaft 83 meshes with a gear 93 keyed to themotor drive shaft 90. An arm 95 secured to and forming an extension ofarm 89 supports one end of a tension spring 96 anchored to pin 72 and iseffective to pivot arms 39 and 95 counterclockwise about the axis ofmotor shaft 90 thereby to press drive pulleys 62 against the drivingflange of turntable 48.

The slide transfer mechanism The transfer mechanism 99 for shiftingthese slides back and forth between the two magazines and the slideprojecting slot 24 of assembly 19 is shown schematically in itsessential operating aspects in the lower right-hand corner of FIGURE 10.This mechanism includes a pair of rigid U-shaped members 100, 101 facingtoward one another and lying in a vertical plane diametrically of thetwo slide magazines A, B. The lower leg of member 100 is telescopicallyengaged with the adjacent lower leg portion of member 101 and includes acompression spring 102 urging the two members horizontally away from oneanother and against a lost motion limiting stop, the purpose of thislost motion resilient connection being to compensate for overtravel ofmember 101 under the driving action of its actuating motor. The upperleg of each member is provided with a hook 103, 103 engageable behindthe complementally shaped downwardly directed hooks 32, 32 of the slidesin magazines A and B. It will be understood that in all index positionsof the two magazines, hooks 103, 103 of the particular two slides thenaligned with the transfer mechanism 99 will be engaged behind the hooksof a slide in respective magazines A and B. Also of importance is thefact that in any index position of the two magazines, a slide from onemagazine is always located in projecting position within projectingassembly 19, whereas the other transfer hook is always engaged with aslide positioned in one of the magazines. As shown in FIG- URE 10,transfer mechanism 99 is located to the righthand end of its path oftravel and a slide from magazine A is located within the projector whilethe other slide engaged with hook 103 is fully seated in magazine B.Consequently, upon reverse shifting movement of the transfer mechanism,slide A will be transferred back into magazine A while the engaged slidefrom magazine B will be transferred into the projecting assembly, itbeing understood that the transfer mechanism always operates from one tothe other of its two extreme positions and then dwells there untilreceiving a signal for the next operating movement.

One of the two U-shaped transfer members, as member 101, is providedwith rack teeth 105 on its lower edge engaged with the teeth of adriving sector 106 mounted on a stationary pivot shaft 107. The drivingmotor 108 for the slide transfer mechanism is coupled through speedreduction gearing 109 and a crank 110 to reciprocate sector 106 back andforth about pivot pin 107. The described to-and-fro movement of transfermechanism 99 is under the control of a cam wheel 112 fixed to shaft 113of the speed reduction gearing. Cam wheel 112 carries a pin engageablewith the operating lever of a two-position switch 115 while a boss 116on the periphery of cam wheel 112 operates a two-position control switch118. The manner in which cam wheel 112 operates switches 115 and 118 tolimit travel of the slide transfer mechanism as well as to controlenergization of solenoids 75, 75' will be described in greater detail inconnection with the projector control circuit.

The slide selector contactors and their disposition relative to theslide magazines The simple but highly effective arrangement of the slideselector contactors and the manner in which these are mounted partlywithin the magazine drums and partly Within the stationary bossesprojecting into the magazine wells will now be described by the aid ofFIGURES 4 and 6.

Magazines A and B as shown herein are equipped to store 48 slidesrespectively, or a total 96. The manner in which any particular slide ineither magazine is designated and in which the magazine containing thedesignated slide is indexed into the proper position to dispense thisslide into the projecting assembly forms a most important feature of theinvention and involves the construction and operation of the contactorsnow to be described. Before proceeding to do so it is pointed out thatthe slides of each magazine are arbitrarily divided into groups of ten.For each of these groups there is an elongated arcuate group or tenscontactor, the several group contactors being arranged in a circle andsupported in an insulated member mounted in the top of stationary boss42 of the projector frame. Disposed radially opposite one of the groupcon-tactors is an arcuate row of ten contactors known as unitscontactors and each respresenting a particular one of the slides of atens group. Referring to FIGURE 6 representing a top plan view of boss42, it will be noted that an insulation disc 120 is suitably supportedWithin the upper end of the boss. Embedded within insulation 120 arefive identical tens contactors 121, 122, 123 124, 125, or one for eachgroup of ten slides within magazine A. Arranged exteriorly along theedge of one of the tens contactors, as contactor 121, are ten individualunits contactors 126, the end two of which are shorter than theremainder for purposes to be described later. Of importance is the factthat each of the units contactors 126 is spaced apart circumferentiallyof the boss by the same distance as are the slide cells 30 Within therespective magazines.

Overlying the described units and tens contactors are a number ofbridging contactors mounted in the disc 34 forming the bottom ofmagazine well 33. These bridging contactors are so positioned andconnected as to complete a circuit between a particular one of the tenscontactors 121 to 125 and a particular one of the units contactors 126as the magazine is indexed about boss 32.

These bridging contactors include wiping conductors resilientlysupported in disc 34 and arranged in three concentric rows, including asingle inner contactor 128, four intermediate contactors 129, 130, 131and 132, respectively, and a single outer contactor 133. Inner contactor128 wipes over the group of tens contactors 121 to 125; the intermediateones 129 to 132 wipe over each of the units contactors 126 including thetwo radially short contactors, and the outer contactor 133 has wipingcontact with all of the units contactors except the two radially shortones. Each of the described wiping contactors 128 to 133 areelectrically interconnected by a common conductor wire 135.

In view of the foregoing, it will be apparent that as the magazine andthe wiping contacts carried thereby rotate relative to the stationaryunits and tens contactors strips on boss 42, the interconnected wipers128 and 12? will close a circuit instantly that they simultaneouslycontact an energized pair of units and tens contactors. By the time themagazine has been rotated sufficiently to carry wipers 128, 129 to theone oclock position (as viewed in FIGURE 6) these wipers will be out ofrange for selecting slides represented by the tens contactor 121.Further clockwise rotation of the magazine renders wipers 132, 131, 130and 133 successively effective to search the units contactors asrespects successive ones of the tens contactors. For example all tenslides represented by tens contactor 122 are next searched by contactor128 as the latter moves along contactor 122 and as contactor 132connected in circuit therewith passes successively over units contactors126. Accordingly, rotation of the magazine from the one oclock positionto the three oclock position will be effective to designate one of theparticular sides within the second tens group. Each of the other tenscontactors 123, 124 and 125 will be brought within the selective rangeof the wipers 131, 130 and 133 in succession and in that order as themagazine continues to rotate clockwise as viewed in FIG- URE 6. It isalso pointed out that since each magazine is provided with only 48slides, or two less than five groups of ten, the last two unitscontactors 126 are foreshortened so as not to be contacted by wiper 133,it being recalled that wiper 133 is the only one spaced sufiicientlyfrom the axis of rotation as not to contact the two radially short unitscontactors.

The control circuit Referring now to FIGURE showing the essentialdetails of the electric circuitry and the associated components forcontrolling the operation of projector assembly 10, it is pointed outthat the illustrated portion of the wiring circuit is that required toselect the first slide in each of magazines A and B. The unshowncircuits include only those required to select 2 to 48 of each magazinewhich unshown circuits are but a duplication of certain of theconnections shown in FIGURE 10 and constituting the electric leadsbetween the units and the tens buttons of control box 14 and theselector contactors of magazines A and B, as well as the connections toeach of the indicator lamps part of which are located in control unit 14and part of which are located in the slide indicator device 16 (FIGURE1).

Referring now to FIGURE 3, it is pointed out that control box 14 isprovided in its top wall with five tens buttons 140 and ten unitsbuttons 141. Each of tens buttons 140 will be understood as controllingas associated double-pole switch one portion of which is used toenergize a particular one of the tens contactors 121 to 125 of eithermagazine and the other of which energizes a pair of pilot lamps 143,144. Likewise, each of tens buttons 141 controls a pair of switches oneof which is effective to energize a particular one of the tenscontactors of each magazine, whereas the other energizes a pair of pilotlamps 145, 146 having the same functions as pilot lamps 143 and 144.

Control box 14 is also provided with a third set of buttons 142 one ofwhich is designated A and the other B. These buttons are known as themagazine selector buttons and are mechanically interconnected to operateswitches of the type schematically indicated in FIGURE 10 and areeffective, as will appear more fully hereinbelow, to select eithermagazine A or magazine B as the magazine from which the next slide is tobe projected. Associated with each of selector buttons A and B are apair of pilot lamp (FIGURE 10) one of each pair of which is located inthe control box and the other of which is located at the digitalindicator device 16. The lamps associated with the two buttons arepreferably distinctively colored, as green, to designate magazine Awhereas the other have a different distinctive color, as red todesignate magazine B, there being one lamp of each color in box 14 andone in indicator 16. When magazine A is to be'used, button A isdepressed to close the associated switch thereby energizing the greenlamps. This illumines the A button with a green light and similarlycolors the viewing screen of indicator 16. It may be pointed out at thistime that the caps for each of the buttons in control box 14 ispreferably translucent so that the colorless pilot lamp associated witheach illuminates the particular button activated at any time.

Before describing the operation of the control circuit, a briefdescription will be given of the auxiliary components and relays formingessential parts of this circuit. Thus, the projector includes a manuallyoperated main switch 150 which is of the double-throw, triple-pole typeand has an operating handle mounted in panel plate 26 secured to the topof housing 25 (FIGURE 2). When closed upwardly, this switch conditionsthe circuit for normal operation to project slides, whereas when it isclosed in the opposite direction, the projector is conditioned foreither loading or demounting of the magazines for servicing. In theintermediate position of switch 150, all circuits controlled thereby areopen.

A third switch 151 mounted in switch mounting panel 26 is operable tocontrol slide transfer mechanism 99 provided main switch 150 is firstclosed downwardly to its loading position. Switch 151 (at the bottom ofFIG- URE 10) can then be manipulated to energize the slide transfermotor 108 to assure that the slides of the particular magazine to bedetached are first transferred into the magazine before it is removedfrom the projector. Thus, assuming that the operator desires to removemagazine A while one of its slides is present in the projector as mainswitch 150 is closed downwardly to its loading position. In this case,he makes certain that switch 151 is closed to its A or left-handposition thereby energizing slide transfer motor 108 to shift the slidefrom the projector back into magazine A. Upon completion of thisoperation, the operator removes magazine A along with its full charge ofslides.

Other important components of the control circuit include a motor-drivenair blower 153 located within the projecting lamp housing 20; an AC. toDC. power converter 154; a starter relay 155 having a normally closedmanual switch 156 connecting it in circuit across the DC. power outletsof converter 154; a slide selection relay 158; a time delay relay 159; alamp relay 160 controlling the power supply to the slide projection lamp161; and a selection relay 162 for determining which of the magazineswill supply the next slide to the projector.

The following characteristics of the several relays will be helpful inunderstanding the operation of the control circuit. Thus, the twocircuits controlled by starter relay 155 are closed only when the manualswitch 156 is closed and power is being supplied to power converter 154.The contactors of slide selection relay 158 are normally closeddownwardly when the relay is de-energized and close upwardly only whenthe relay is energized, a condition existing only when one or the othermagazine has rotated into position for the transfer of a selected slideinto the projecting assembly. Time delay relay 159 is normally open asshown in FIGURE and its contactor closes slowly a measured time intervalof A2 to 1 second after its coil is energized. The time delay constantof the relay of one-half to one full second safeguards against startingof the turntable drive motors 91, 91 while the slide transfer mechanismis still in movement and thereby avoids the possibility of jamming theturntables and the slides carried thereby. The lamp relay closes theprojection lamp circuit to lamp 161 each time this relay is energized,whereas the magazine selection relay 162 reverses the position of itsnumerous contactors each time it is energized and de-energized. Thepower supply to the magazine selection relay is controlled by selectorswitch 142 having a pair of buttons designated A and B, respectively,interconnected by a toggle bar and effective to hold the switchesactuated thereby in one of two positions depending upon which of itsoperating buttons A or B is depressed. The spring biasing these buttonsis effective to hold either button in its lower position in accordancewith toggle switch technique well known to the art.

Operation with random slide selection first from magazine A and thenfrom magazine B Let it be assumed that the projector is set up and readyfor projection of slides from the fully charged cells of both magazines.Also let it be assumed that power is supplied from a standard 110 voltA.C. source as is indicated at 170 at the top of FIGURn 10. First mainpower switch 150 is shifted to its on position to supply power to theprojector and to the A.C.-to-D.C. power converter 154 as well as to airblower 155. Let it further be assumed that manual switch 156 on theoutlet side of converter 154 is closed to energize starter relay 155 toclose its contacts controlling the supply of direct current to thevarious components energized thereby.

In the position of the parts shown in FIGURE 10, slide No. 01 frommagazine A is located in the projector and the lamp relay 161i isenergized to supply power to projection lamp 161. Under these conditionsthe units button 141 is lighted by its uncolored pilot lamp 145 and thecorresponding lamp 146 of the digital readout indicator 16 is alsolighted thereby indicating to the audience that slide No. 1 is beingexhibited. Also button A of the magazine selector switch 142 isdepressed and the characteristic green colored light illuminates the Abutton of the control box 14, as well as the screen of indicator 16.

Now let is be assumed that the operator wishes to project slide No. 01from magazine B. To do so, he first depresses button B of magazineselector switch 142 thereby opening the previously closed switchassociated with the A button and shifting the B button to its alternateor closed switch position, the switch being held in the alternateposition by the action of the spring forming part of the toggleoperating mechanism of switch 142. Depression of the B buttonde-energizes the green indicator lamps for the A switch and closes thered indicator lights of the B button thereby indicating that the Bmagazine is to be operated nextv Not only is the B button illuiminatedin red but so is the screen of indicator device 16 thereby notifying theaudience that the B magazine is being used. Depression of the B buttonalso closes the circuit through the magazine selection relay 1&2 toshift the four movable contactors of this relay from the upper to thelower closed positions thereof, thereby conditioning the apparatus forthe projection of one or more slides from the B magazine. All thatremains is for the operator to select a slide to be projected. Assumingthat slide number one is the selection, the operator depresses unitsbutton No. 1 in control unit 14 and the tens zero button. The tensbutton, represented by character 140 in FIGURES 3 and 10, has itsright-hand switch contact connected to the negative bus of the DC. powersupply 154 and its left-hand contact 1% connected through the upper butdownwardly closed contact of A-B relay 162 to the zero group of tenscontactor 121. Also, the right-hand upper switch contact of the No. 1units button, represented by character 141 in FIG- URES 3 and 10, ispermanently connected to the first one of the units contactors 126' ofmagazine B, its left-hand side being connected to the upper lead of theslide selection relay 158. The lower lead of this relay is connectedthrough lead 171) to the plus side of the DC. power supply.

At this time, relay 158 is not energized because the bridging contactorsof magazine B are not in position to bridge and close the circuitbetween tens contactor 121 and units contactor 126'. Accordingly, thecontacts of relay 158 remain closed downwardly. Accordingly, current nowflows from one side of the A.C. supply through lead 171, the downwardlyclosed upper contact of selection relay 158, lead 172 through thedownwardly closed No. 3 contact of relay 162, through lead 173 to themovable contact of microswitch 118, through its lower contact and lead174 to solenoid 75, and thence through lead 175 to the downwardly closedcontact of time delay relay 159 and along lead 176 through thedownwardly closed lower contact of selection relay 158, and through lead177 to the other side of the AC. power supply. Normally, the contactorof time delay relay 159 is open as shown in FIGURE 10, but this relay isenergized to close its contactor as an incident to de-energization ofselection relay 158, the current supply being through lead 177 and thelower contactor of relay 158, lead 176, through the relay and to theother side of the supply source via lead 17 8. As has been pointed out,the time delay relay closes downwardly slowly and after a delay ofone-half to one second. However, as soon as it does close, theabove-described current flow takes place thereby energizing solenoid 75'to retract turntable pawl 67 and reverse the position of microswitch 83to start turntable motor 91. In other words, energization of thesolenoid retracts pawl 67' thereby freeing the B magazine turntable 48'for rotation by its drive motor 91 and drive pulley 62'. The powersupply to motor 91' is derived through lead 184) and flows through themotor, through the left-hand contact of switch 83 and back to the otherside of the power supply via lead 181.

The turntable now continues to rotate carrying with it the magazine andbridging contactors 135'. As soon as the bridging contacts close againstzero contactors strip 121 and the units contactor 126, the circuit isclosed to energize selection relay 158 and close its two movablecontacts upwardly thereby de-energizing solenoid 75 allowing the spring'71 to seat pawl 67 within the underlying notch 61). This actionpositively locks turntable 43 and its interlocked magazine againstrotation and with the selected slide No. 01 opposite its transferposition into the slide projecting station.

Slide transfer mechanism 99 is automatically activated at this point totransfer slide No. 01 from magazine B into the projecting station. Thepower to drive slide transfer motor 108 is derived from the left-handside of the power circuit and flows through lead 171 to the upwardlyclosed upper contactor of selection relay 158, thence through lead 185to the lower and downwardly closed number 4 contactor of A-B relay 162,along lead 186 to microswitch 115 now closed to the right, along lead186 to motor 108 and thence along lead 187, through microswitch 83,along lead 172, through microswitch 83' and along lead 181 to the otherside of the power supply. The energized motor 1138 now operates throughits gearing to drive link 1111 and toothed sector 106 to shift slidetransfer members 100, 161 to the left thereby simultaneously retrievingthe slide present in the projector back into magazine A While shiftingslide No. 01 from magazine B into the projecting station. motor isconnected by shaft 113 to rotate cam member 112, it will be understoodthat the retrieval of slide B into the magazine occurs as pin 114 ondisc 112 contacts Since the transfer microswitch 115 to close it to theleft. Before switch 115 closes to the left it will be understood thatthe high section 116 on cam disc 112 rotates clockwise allowing thefollower roller of microswitch 118 to close the latter upwardly. Thedescribed reversal of switch 115 discontinues the power supply to motor108 leaving slide A in its magazine and leaving slide No. 01 of magazineB in the projecting station; additionally the reversal of microswitch115 energizes the projection lamp. Thus, as switch 115 closes to theleft, current flows through lead 188 to lower contact of AB relaycontactor No. 2, thence through the coil of lamp relay 160, and throughlead 189 back to the other side of the power Source by way of main powerswitch 150. The energization of lamp relay 166 then closes the powercircuit to the projection lamp 161.

Let it now be assumed that the operator wishes to show the next slidefrom magazine A. Inasmuch as the duplicate circuits for each of theslides of this magazine have been omitted for simplicity ofillustration, we will assume that slide No. ()1 of magazine A is the oneselected. It will be recalled that magazine A was already in position todispense slide No. 01. Accordingly, throughout the period of use ofmagazine B, locking pawl 67 of the A magazine remains seated in thenotch 60 corresponding to slide No. 01; for this reason the A magazinehas remained locked and in position to again display its slide No. 01.Irrespective of this fact, to display any slide from magazine A theoperator must first condition the projector for this purpose which isdone simply by depressing the A button of the magazine selector switch142. This de-energizes the A-B relay 162 allowing its four contactors toclose upwardly. The selection relay is momentarily de-energized butsince bridging contact 135 of the A magazine is already positioned tocomplete a circuit through its Zero tens contactor 121, and the No. 1units contactor 126, relay 158 is immediately re-energized to retain itstwo contactors closed upwardly. It will be recalled that the lastposition of slide transfer motor 108 was with microswitch 115 closed tothe left and microswitch 118 closed upwardly. Hence, motor 108 isenergized immediately to transfer slide No. 01 (derived from magazine)back into the B magazine while simultaneously transferring slide No. 01from the A magazine into projecting position. The circuit by which thisis accomplished includes the upper contactor of selection relay 158,lead 185, the upwardly closed No. 4 contactor of A-B relay 162, lead173, the upwardly closed contact of switch 118, lead 190, motor 108,lead 187, the two microswitches 83, 83, lead 172 and lead 181. As Amagazine slide No. 1 becomes seated in the projector, projection 116 ofcam 112 closes switch 118 downwardly thereby de-energizing slide motor108 and supplying power through lead 192 and the upwardly closedcontactor No. 2 of the A-B relay to lamp relay 160 thereby re-energizingthe projector lamp circuit.

Had magazine not been in the proper position to load slide No. 01 intothe projecting station, the operator would have depressed the tens zerobutton and the units 01 button thereby conditioning the slide selectorcontactors to energize the selector relay as soon as magazine A isrotated into the proper loading station for slide No. 01, i.e., whenbridging contactor 135 makes contact with zero tens contactor 121 andthe first one of the units contactor 126.

It should also be pointed out at this point that the depression of bothzero buttons operates on the starter relay to open switch 156 thereby toplace the system in standby condition with only the power converterassembly energized.

It will also be understood that the conventional control box 14 is soconstructed that only one units and one tens button can be depressed atany one time. Also the depression of the 4th tens button and the ninthunits button is preferably arranged to lock both magazines out ofoperation. Likewise manually actuated switch 152 is operable when opento deactivate magazine B as is desirable when only magazine A is usedand is charged with slides. This safeguards against an accidentalattempt to load a slide from empty magazine B through preventing therotation of the turntable ring 48' which carries that magazine.

Detachment 0f the magazines for servicing Let it now be assumed that theoperator wishes to remove the A magazine from the projector for somereason.

The first step is to reverse the position of main switch 150 to close itdownwardly. This deactivates the power supply to power converter 154 todiscontinue the supply of DC. to all components in circuit therewith.However, AC. power continues to be supplied to the blower fan 153'tocirculate cooling air over the projection lamp. In addition, AC. poweris supplied from main switch 150 through lead 195 to a circuitcontaining a magazine selector switch 151.

Before removing either magazine it is important that all slides of thatmagazine be in their proper cells and that none be present in projectorassembly 19. Since slide 1 of magazine A is now in the projector it isfirst necessary to return this slide into the magazine. Accordingly, theoperator shifts switch 151 to its A position as indicated by the letterA thereon. Current now flows from the downwardly closed main switch 150,through lead 195, switch 151, lead 196 to the blade of switch now closedto the right. The current then flows through lead 186 to motor 108 andback to the other side of the line through lead 187, switch 83, lead172, switch 83 and lead 181. Mechanism 99 now functions to return tomagazine A while inserting a slide from magazine B into the projector.As soon as the slide has been returned to magazine A, motor 108 isde-energized by the opening of switch 115, but shortly before thisoccurs, microswitch 118 controlling the operation of the transfer motor108 has been closed upwardly thereby conditioning the transfer motorcircuit to relieve the B magazine back into its magazine subject only tothe shifting of switch 151 to its B position; following the secondretrieval operation, the B magazine can also be removed, leaving bothturntables unoccupied. It would, of course, be understood that theretrieval of the second slide is delayed until magazine A has beendetached from its turntable. Before lifting either magazine from theturntable, the operator takes the precaution of placing a guard bandaround the periphery of the magazine to prevent accidental loss ofslides from their respective cells.

Let it now be further assumed that the operator performs some servicework and is ready to return magazine A to its turntable. This isaccomplished merely by placing the magazine over boss 42 and twisting itto the right or the left, if necessary, until locator 55 on theturntable seats in any one of the recesses 56 arranged about the bottomof the magazine. Before removal of the magazine slide No. 1 was alignedwith the projection slot 24. Constituting the slide projecting stationlet it be assumed that when the magazine was returned haphazardly to theturntable slide No. 46 rather than slide No. 1 is the one aligned withthe projecting station. This fact in no wise interferes with the abilityof the equipment immediately to locate and select any slide, as slideNo. 1 for insertion since a magazine is brought automatically back intoits proper aligning position without need for the operator performingany special operation. This is accomplished merely by re-closing mainswitch 150 in its upper or normal operating position. Since the controlbuttons of box 14 have not been disturbed, the projector is conditionedfor the selection, loading and projection of slide No. 1 from themagazine in the following manner.

Since the A magazine is out of its proper projecting position, itsbridging contacts are open circuited and power supply to selection relay158 is incomplete. Hence, this relay is closed downwardly. It will berecalled that in the last-described position of slide transfer controlcams 112, switch 115 was closed to the left, as is necessary for allslides to be stored within magazine A. Accordingly microswitch 115 iscorrectly positioned to activate locking solenoid 75 of the A magazine.

Power for energizing solenoid 75 is derived through lead 171, thedownwardly closed upper contactor of selection relay 185, lead 172, theupwardly closed No. 3 contactor of AB relay 162, lead 186, switch 115closed to the left, solenoid 75 and through the downwardly closedcontactor of time delay relay 175, lead 176, the downwardly closed lowercontactor of relay 158 and back to the other side of the line via lead177. The activation of solenoid 75 closes the turntable control switchto the left to drive the turntable until bridging contactors 135complete the selection relay power circuit through tens contactor 121and the No. 1 units contactor 126 of magazine A. This instantlyenergizes selection relay 158, thereby discontinuing the power supply tosolenoid 75, closing switch 83 to the left, and allowing pawl 67 to lockthe turntable against rotation. Switch 83 now supplies power to motor108 to transfer slide No. 1 from the magazine into the projectorwhereupon the lamp relay closes to energize projection lamp 161.

It is therefore seen that the magazines can be removed and replaced inany position whatever without confusing the controls or affecting theproficiency of these to locate and load any desired slide into theprojector automatically and without any special preliminary operation.

While the particular remote control slide projector herein shown anddisclosed in detail is fully capable of attaining the objects andproviding the advantages hereinbefore stated, it is to be understoodthat it is merely illustrative of the presently preferred embodiments ofthe invention and that no limitations are intended to the details ofconstruction or design herein shown other than as defined in theappended claims.

I claim:

1. A remote control image projector of the type having a projectionlight and lens assembly for projecting an image onto a screen inenlarged form, that improvement which includes rotary magazine means fornormally compactly storing a series of images on image-bearing media inclose side-byside relation in readiness for transfer into projectingposition in said image projecting assembly, remote control meansoperable to rotate said magazine means until an individual imageselected successively in any random order is in a predetermined positionand for thereupon transferring the selected image edgewise in the planeof said image for a distance not substantially greater than the lengthof the image-bearing media and individually into projecting position insaid image projecting assembly and including means for retrieving apreviously selected image back into a predetermined storage positiontherefor in said magazine before permitting said magazine to rotate to aposition for displaying the next image selected at random.

2. An image projector as defined in claim 1 characterized in that saidimage magazine means and the remote slide selection and transfer meansincludes power means operable to move said magazine means bodilyrelative to said image projecting assembly to align a selected imagelaterally opposite the image projecting position thereof in saidprojecting assembly, and means for locking said magazine means in saidlast mentioned position while the selected image is being transferrededgewise into said projection assembly and returned to its formerposition in the magazine.

3. An image projector as defined in claim 2 characterized in theprovision of means for energizing said image projecting light only whilean image is centered in said projecting assembly.

4. An image projector as defined in claim 1 char acterized in that saidmagazine means includes a powerdriven turntable detachably supportingsaid magazine means and in that the latter comprises a circular storagedrum for storing a plurality of image-bearing slides therein, said drumhaving radially disposed slide supporting cells opening outwardlythrough the periphery thereof and through which openings slides may beinserted and withdrawn, and said control means including poweroperatedreciprocable slide transfer means for transferring a selected slidebetween a cell therefor in said magazine and said slide projectingassembly.

5. An image projector as defined in claim 1 characterized in theprovision of electrical indicator means operatively associated with saidcontrol means and operable to energize a signal visible to the observerof the projected image and identifying and distinguishing a particularimage from all others in said magazine means.

6. An image projector as defined in claim 1 characterized in that saidimage magazine means comprises a power-driven turntable and a readilyremovable circular drum containing a ring of image-bearing slidereceiving cells arranged about the peripheral portion thereof, saidcircular drum resting on said turntable and being removable therefrom bylifting the same away from said turntable, and readily separableinterlock means between said drum and said turntable for causing saiddrum to interlock and rotate with said turntable when resting thereon inany one of a plurality of different positions and for assuring precisionalignment of the slide cells in the drum with said turntable in each ofa plurality of different interlockable positions.

7. An image projector as defined in claim 1 characterized in theprovision of positive brake means for said turntable operable toposition the turntable and a slide cell of said drum in accuratelyaligned planar relationship with a slide projecting position within saidslide projecting assembly to facilitate trouble-free transfer of a slidebetween said drum and said projecting assembly.

8. An image projector as defined in claim 1 characterized in theprovision of a plurality of independent slide magazine meansindividually removable as a unit from said projector and locatedlaterally to either side of said image projection assembly and furthercharacterized in that said remote control means is operable at the usersoption to select and to project any desired image-bearing slide atrandom from any one of said magazine means.

9. In a slide projector for use in projecting a magnified image on aviewing screen, said projector having a slide projecting assembly, apower-driven turntable positioned closely adjacent one side of saidprojecting assembly, a plurality of stationary electrical contactorssupported on said projector in close proximity to said turntable, amagazine drum having a plurality of slide seating cells opening throughthe wall thereof and movable past a transfer position with respect tosaid slide projecting assembly, power-driven means operable to transfera slide between said drum and projecting assembly, control meansincluding selection means for said projector including connections tothe drive means for said turntable and for said slide transfer means,said control means including electrical conducting means carried by saidmagazine for contacting said contactors as said magazine rotatesrelative thereto, and brake means for said turntable controlled by thecompletion of an electrical circuit through said contactors and themeans in said magazine drum to assure stoppage of said magazine drum inaccurate slide transfer position with respect to said slide projectingassembly as said drum rotates to the proper position for the transfer ofthe selected slide into projecting position.

10. A remote control slide projector having a main frame supportingimage projecting means thereon, slide magazine means movably supportedon said main frame transversely of a slide transfer position betweensaid magazine and said image projecting means and including means formoving said magazine means therepast, a series of stationary contactors,other contactors movable with said magazine means and traversing saidstationary contactors as said magazine is indexed therepast, a pluralityof normally open slide selection switches in circuit with saidstationary contactors, and means responsive to the arrival of theselected slide at its projection transfer position to lock said magazineagainst movement and to transfer the selected slide into projectingposition.

11. A slide projector as defined in claim characterized in that saidslide magazine means includes a unitary slide magazine and a movablesupport therefor, and further characterized in that said unitary slidemagazine is readily detachable from said movable support along with thecontactors movable therewith.

12. That improvement in a remotely controlled slide projector whichcomprises a cylindrical slide magazine having a well opening axiallythrough its lower end and adapted to seat over a complementally shapedboss of a projector assembly, said magazine having a plurality ofradially disposed slide receiving cells arranged about said Well andopening through the outer rim of said magazine, and a plurality ofelectrical contactors mounted in the bottom of said well and havingresiliently supported ends arranged in predetermined spaced relation toone another and adapted to engage slide-selecting contactors supportedon the projector assembly boss when said magazine is assembled thereoverand rotated thereabout.

13. That improvement defined in claim 12 characterized in that the topend wall of said cylindrical magazine is provided with a handgrip bywhich the magazine can be assembled over and lifted from said projectorboss.

14. In a slide projector of the type having a slide projecting assemblyand a rotary magazine support rigidly supported to one lateral sidethereof, that improvement which comprises, a boss projecting verticallyfrom said magazine support, a turntable ring journaled about the base ofsaid boss, a slide magazine drum having a centrally-disposeddownwardly-opening well shaped to fit over said boss and to be supportedon said ring for rotation therewith, said magazine having slidereceiving cells opening through the peripheral side wall thereof androtatable into position for the transfer of a designated slide into saidprojecting assembly, and cooperating electrical contactors some of whichare mounted on said boss and some in said well and adapted to beconnected in a slide selection control circuit including means thereinoperable to rotate said magazine until a selected slide is aligned withsaid position for the transfer of the selected slide into the projectingassembly.

15. A slide projector as defined in claim 14 characterized in that saidboss includes an annular keeper flange adapted to have interlockingengagement with cooperating detent means on slides present in saidmagazine, said keeper flange having a notch therein disposed inalignment with the position of said magazine for transferring a slideinto and out of said slide projecting assembly and through which notchsaid slide detent means of a slide is freely movable.

16. A slide projector as defined in claim 14 characterized in that thecontactors mounted on said boss are arranged in two rows, one of saidrows having circumferentially narrow units contactors each correspondingto a different slide within a group of slides and the other of said rowshaving a plurality of long tens contactors each having a lengthcorresponding generally to the combined space occupied by said unitscontactors, said contactors mounted on said magazine drum comprising aplurality of bridging conductors having their ends disposed in Wipingcontact respectively with units and tens contactors and arranged tobridge a particular pair only of said units and tens contactors in anyrotary position of said magazine thereby to activate a selection controlcircuit for the particular slide in said magazine associated with saidparticular pair of bridged contactors.

17. A slide projector as defined in claim 16 characterized in that saidbridging contactors are spaced apart circumferentially of said magazineby a distance corresponding approximately to the length of said tenscontactors and each adapted to control the selection and transfer of adifferent group of slides carried within said magazine.

18. A slide projector as defined in claim 14 characterized in that saidturntable ring includes an annular peripheral surface and a drivenpulley engaged therewith for rotating said ring about said boss, andsaid ring having a separate notch therein positioned in radial alignmentwith each slide receiving cell of said magazine, and fastaction latchmeans movably supported on said projector adjacent said notches andmovable into and out of engagement therewith to control stopping of saidring with a selected slide cell precisely aligned opposite the slideprojecting position of said projecting assembly.

19. In an automatic slide projector, that improvement which comprises amain frame having a slide projecting assembly thereon provided wit-h aslide receiving station, a magazine turntable on said frame disposedlaterally of said slide receiving station, a slide magazine removablysupported on said turntable housing a plurality of slides adapted to betransferred in random order between said magazine and said slideprojecting assembly, separable means for positively locking said slidemagazine to rotate with said turntable when seated thereon in any one ofseveral different positions, means for rotating said turntable andmagazine as a unit, means for locking said turntable against movementand for stopping the same precisely in any one of a plurality ofpredetermined positions during any particular positioning operationthereof,

and means for rotating said turntable until a particular slide selectedat random is accurately aligned with said slide receiving station.

20. The improvement defined in claim 19 characterized in the provisionof control means operatively associated with said turntable lockingmeans for activating said turntable rotating means as an incident tounlocking the turntable for rotation and for relocking said turntable asrotation of the turntable is discontinued.

21. An image projector device and remote control circuit for selectivelytransferring at random any of a plurality of image-bearingtransparencies from a storage position therefor into projecting positionand for returning the same back into storage position while transferringanother random selected image into projecting position, said circuitincluding image selector means for selecting any stored image in anyorder, said image selector means 1ncluding manually operable imageselector switch means comprising a plurality of units selector switchmeans and a plurality of tens selector switch means and including meanscooperating with one another to designate a particular image fortransfer into image projecting position, means responsive to anindicated selection by said selector means to transfer the selectedimage into means for projecting the selected image in enlarged form ontoa screen, means for locking the remaining ones of said images in storageposition while any selected image is in use, and means activated by theselection of any other image to return the previously selected image tostorage position and thereupon to initiate the transfer of the nextselection into projecting position.

22. An image projector device and control circuit as defined in claim 21characterized in that said image projector includes a lamp connected insaid circuit, and means for discontinuing the light beam through animage while being transferred between storage and projecting positions.

23. An image projector device and control circuit as defined in claim 21characterized in the provision of a pair of image storage means andincluding selector means for designating a particular one of saidstorage means as the one from which the next image is to be selected forpro jection, and said image selector being operable to cycle 17 saidcontrol circuit to retrieve the previous image selection into its properstorage position and to advance the newly selected image to and thetransfer of the selected image from the other storage means intoprojecting positron.

24. An image projector device and control circuit as defined in claim 23characterized in the provision of means in said control circuit forlocking both image storage means immovably in place except when an imagefrom one thereof is in an initial stage of movement toward itsprojecting position in said projector.

25. An image projector device and control circuit as defined in claim 23characterized in that each of said image storage means is circular,separate power-driven rotary means supporting each of said circularstorage means, and said means for locking said storage means immovablyin place comprising separate solenoid-operated detent means connected insaid control circuit and operatively associated with each of saidstorage means.

26. An image projector device and control circuit as defined in claim 21characterized in the provision of electrically energized indicator meansactivated while an image is being projected onto the viewing screen andeffective to identify to the audience the particular image being shown.

27. An image projector device and control circuit as defined in claim 23characterized in the provision of image indicator means connected tosaid circuit and operable to inform the audience by symbol which imageis being projected and including means intelligible to the projectoroperator for indicating from which storage means the image came.

28. In combination with a slide projector having a main frame supportinga slide projecting assembly thereon and having an upstanding circularboss offset laterally from a slide receiving slot extending crosswise ofthe projecting assembly, that improvement which comprises meansrotatably supporting a slide magazine turntable concentrically of saidboss, a circular magazine drum detachably supported on said turntableand having slide seating cells arranged radially thereof and openingthrough its exterior side wall, solenoid-operated stop means including aseparate stop for each cell of said magazine movable between engaged anddisengaged positions with respect to said turntable and the magazinemounted thereon and operable when disengaged to permit rotation of saidturntable and when engaged to prevent drive of said turntable, andmotor-drive means for driving said turntable when said stop means isdisengaged.

29. The combination defined in claim 28 characterized in the provisionof a control switch for said turntable drive motor operatively connectedwith said solenoid-operated stop means and arranged to energize saiddrive motor as said stop means is disengaged and to de-energize themotor drive as the stop means re-engages.

30. The combination defined in claim 28 characterized in that said stopmeans includes a pivoting pawl having a tooth engageable selectively inone of a plurality of notches of said turntable and pivoting on astationary support spaced circumferentially from the toothed portion ofsaid pawl, and adjustable means connecting said pawl to the operatingsolenoid therefor, and means normally biasing said pawl into lockingengagement with one of said turntable notches.

31. The combination defined in claim 28 characterized in the provisionof slide selector control means for controlling said turntable drivemotor including a plurality of contactors mounted on said boss and aplurality of cooperating bridging contact means positioned to wipe oversaid contactors as said turntable rotates and connected in circuit withslide selector means, said contactors and bridging contact meanscooperating with said slide selector means and with said turntable drivemotor and the stop means therefor to position any selected slide in saidmagazine selected at random in transfer alignment with the slide seatingslot in said projecting assembly, and means for transferring a selectedslide between said magazine and said projecting assembly while saidturntable remains stationary.

32. The combination defined in claims 28 characterized in that saidmotor drive for said turntable includes a motor having a gear wheelfixed to its driven shaft, an arm pivotal about the axis of said shaft,a shaft mounted in said arm having fixed thereto a driven gear meshingwith said gear wheel, a soft-surfaced drive pulley on said lastmentioned shaft positioned to engage an annular drive flange carried bysaid turntable, and means for biasing said drive pulley into firmfrictional contact with said drive flange.

References Cited by the Examiner UNITED STATES PATENTS 1,349,640 8/ 1920Trueblood 88-27 2,076,924 4/1937 Spindler 8828 X 2,748,653 6/1956 Pollanet a1. 3,023,669 3/1962 Hall 88-28 OTHER REFERENCES German application1,109,404, Pioch, June 22, 1961. Hairabedian: Random Access to Slides,IBM Technical Disclosure Bulletin, vol. 3, No. 2, page 15, July 1960.

NORTON ANSHER, Primary Examiner.

WILLIAM MISIEK, Examiner.

1. A REMOTE CONTROL IMAGE PROJECTOR FOR THE TYPE HAVING A PROJECTIONLIGHT AND LENS ASSEMBLY FOR PROJECTING AN IMAGE ONTO A SCREEN INENLARGED FORM, THAT IMPROVEMENT WHICH INCLUDES ROTARY MAGAZINE MEANS FORNORMALLY COMPACTLY STORING A SERIES OF IMAGES ON IMAGE-BEARING MEDIA INCLOSE SIDE-BY-SIDE RELATION IN READINESS FOR TRANSFER INTO PROJECTINGPOSITION IN SAID IMAGE PROJECTING ASSEMBLY, REMOTE CONTROL MEANSOPERABLE TO ROTATE SAID MAGAZINE MEANS UNTIL AN INDIVIDUAL IMAGESELECTED SUCCESSIVELY IN ANY RANDOM ORDER IS IN A PREDETERMINED POSITIONAND FOR THEREUPON TRANSFERRING THE SELECTED IMAGE EDGEWISE IN THE PLANEOF SAID IMAGE FOR A DISTANCE NOT SUBSTANTIALLY GREATER THAN THE LENGTHOF THE IMAGE-BEARING MEDIA AND INDIVIDUALLY INTO PROJECTING POSITION INSAID IMAGE PROJECTING ASSEMBLY AND INCLUDING MEANS FOR RETRIEVING APREVIOUSLY SELECTED IMAGE BACK INTO A PREDETERMINED STORAGE POSITIONTHEREOF IN SAID MAGAZINE BEFORE PERMITTING SAID MAGAZINE TO ROTATE TO APOSITION FOR DISPLAYING THE NEXT IMAGE SELECTED AT RANDOM.